Sir Alex Ferguson believes Manchester United are well positioned to retain the Premier League title but claims their defence could yet unravel.

Chelsea's 1-1 draw at Wigan on Monday night has left United's nearest
challengers trailing by five points with four games remaining.

It would take a major collapse for the league leaders to surrender their
advantage and they could be crowned champions at Stamford Bridge on April 26.

But a cautious Ferguson, who tonight presented a Nationwide Lifetime
Achievement award to Denis Law, insists there is still time for one more twist.

'Wigan's draw with Chelsea puts us in a good position but in my experience in
life you don't take things for granted,' he said.

'We've got some difficult games ahead - Blackburn, West Ham, Chelsea and
Wigan. We have three away games and one at home so we have to do a job.

'Because we have difficult games left there is still a lot to play for and it
could still go down to the wire.'

Ferguson felt Wigan - managed by former United skipper Steve Bruce - were
rewarded for their bravery against Chelsea.

'I spoke to Steve a couple of times before the game and said I'd sever all
connections with him if he didn't get a result,' he said.

'Steve deserved it because he was brave enough to play three forwards in the
last 20 minutes of the match when Chelsea were dominating and could have been
3-0 up.

'It was a surprise result. Chelsea didn't deserve that but you have to admire
Steve's courage.'

United's position is further strengthened by a goal difference that is
superior to Chelsea's by 19 and Ferguson insists the advantage is reward for his
side's swashbuckling style.

'One of the encouraging things is the goal difference is helping us,' he
said.

'That's deserved because we've attacked all season and have put an attacking
emphasis on our game.

'Cristiano Ronaldo, Wayne Rooney and Tevez have scored over 70 goals between
them. That's a great return from three players.'

United put one hand on the title with Sunday's 2-1 victory over Arsenal and
Ferguson admitted the competition has been ferocious this season.

'It's been a really competitive league,' he said.

'Arsenal and ourselves spent a long time competing for that top spot and
Chelsea have crept us behind us.

'It's very easy to dismiss them now but when we beat Arsenal we knew we were
right back in the ball park of going for it.

'Last night's result was a bonus for us. Our hardest game was at
Middlesbrough earlier this month - we dropped two points there.

'It was a massive result for us against Arsenal. It could still go to the
wire and we can't take it for granted.

'We could lose to Chelsea and we could lose all our remaining games. It's a
very difficult league these days.'

Rio Ferdinand is understood to have provisionally agreed a new deal with
Manchester United that will keep him at Old Trafford for the next five years.

Although Ferdinand still has two years remaining on his current contract,
negotiations regarding an extension had been planned for the summer.

However, Ferdinand is believed to have called for talks to begin sooner rather
than later, and now it is only a matter of the 29-year-old putting pen to
paper.

United are also adamant that Ronaldo is going nowhere either, despite Real
Madrid sporting director Predrag Mijatovic's claim today that they want the
Portuguese superstar to be 'the face' of the Spanish giants in the future.